• Journal of Korea Spatial Information System Society
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• v.1 no.1 s.1
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• pp.57-67
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• 1999

Two GIS and/or OGIS issues for ITS interoperability have been proposed and reviewed with some implications to Korean setting. They are location referencing and ITS map datum. The former must support ITS communication and data sharing. Therefore, an introduction of location referencing and other related issues have been addressed along with the Oak Ridge National Lab.'s (ORNL) location referencing scheme. The latter, proposed by ORNL, is a planned network of anchor points across the nation, that could potentially serve as a positional reference for ITS application (Gottsegen, 1997). It is composed of a set of nodes and links in a standard non-plannar network at a coarse scale for the entire nation for referencing purposes. To provide case of real time traffic information and to guarantee the seamless interoperability, we do need to develop the core ITS map datum as a national infrastructure, and the location referencing scheme should also be either developed or borrowed and localized to meet the domestic needs. Some institutional issues are also addressed along with the future research agenda.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.34-39
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• 2019

Millimeter-wave (mmWave) and Non-orthogonal multiple access (NOMA) are expected to be the major techniques that lead to the next generation wireless communication. NOMA provides a high spectrum efficiency by sharing of spatial resources among users in the same frequency band. Meanwhile, millimeter-wave gives a huge underutilized bandwidth at extremely high frequency band (EHF) which covers 30GHz to 300GHz. These techniques have been proven in several recent literatures to achieve high data rates. The combination of NOMA and millimeter-wave techniques further improves average sum capacities, as well as reduces the interference compared to conventional wireless communication systems. In this paper, we focus on hybrid NOMA system working in millimeter-wave frequency. We propose a clustering algorithm used for a hybrid NOMA scheme to optimize the usage of wireless resources. The proposed clustering algorithm adds several conditions in grouping users and defining clusters to increase the probability of the successful superposition decoding process. The performance of the proposed clustering algorithm is investigated in hybrid NOMA system and compared with the conventional orthogonal multiple access (OMA) scheme.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.803-810
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• 2007

Although synthetic aperture focusing techniques can improve the spatial resolution of ultrasound imaging, they have not been employed in a commercial product because they require a real-time N-channel beamformer with a tremendously increased hardware complexity for simultaneous beamforming along M multiple lines. In this paper, a hardware-efficient beamformer architecture for synthetic aperture focusing is presented. In contrast to the straightforward design using NM delay calculators, the proposed method utilizes only M delay calculators by sharing the same values among the focusing delays which should be calculated at the same time between the N channels for all imaging points along the M scan lines. In general, synthetic aperture beamforming requires M 2-port memories. In the proposed beamformer, the input data for each channel is first upsampled with a 4-fold interpolator and each polyphase component of the interpolator output is stored into a 2-port memory separately, requiring 4M 2-port memories for each channel. By properly limiting the area formed with the synthetic aperture focusing, the input memory buffer can be implemented with only 4 2-port memories and one short multi-port memory.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.5
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• pp.11-17
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• 2016

The purposes of this research are to estimate area of greenable roof and to monitor maintaining of green roofs using World-View 2 images. The contents of this research are development of World-View 2 application technologies for estimation of green roof area and development of monitoring and maintaining of green roofs using World-View 2 images. The available green roof areas in Gwangjin-gu Seoul, a case for this study, were estimated using digital maps and World-View 2 images. The available green roof area is approximately 12.17% ($2,153,700m^2$) of the total area, and the roof vegetation accounts for 0.46% ($80,660m^2$) of the total area. For verification of the extracted roof vegetation, Vworld 3D Desktop map service was applied. The study results may be used as a decision-making tool by the government and local governments in determining the feasibility of green roof projects. In addition, the project implementer may periodically monitor to see whether roof greening has maintained for efficient management of projects, and a vast amount of World-View 2 images may be regularly used before and after the projects to contribute to sharing of satellite images information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.3
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• pp.891-910
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• 2021

Previous QoS-aware service composition methods mainly focus on how to generate composite service with the optimal QoS efficiently for a single request. However, in the real application scenarios, there are multiple service requests and multiple service providers. It is more important to compose services with suboptimal QoS and maintain the load balance between services. To solve this problem, in this paper, we propose a service composition method, named as dynamically change and balancing composition method (DCBC). It assumes that the QoS of service is not static, and the services can adjust the value of QoS to gain more opportunities to be selected for composition. The method mainly includes two steps, which are the preprocessing step and the service selection step. In the preprocessing step, a backward global best QoS calculation is performed which regarding the static and dynamic QoS respectively; then guided by the global QoS, the feasible services can be selected efficiently in the service selection step. The experiments show that the DCBC method can not only improve the overall quality of composite services but also guarantee the fulfill ratio of requests and the load balance of services.

• Spatial Information Research
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• v.13 no.4 s.35
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• pp.365-372
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• 2005

In North Korea, there has been the considerable loss of human lives every year due to the deficiency of foods. Thus, in order to reduce such damages, a research project should be launched to provide various information for cooperation with North Korean government, and to develop proper agricultural information management system. Therefore, this research is mainly to develop North Korean Agricultural Information Management System (NKAIMS), which can collect, manage and analyze agricultural information and water resources utilization status of North Korea, and further support to make relevant decisions and establish the agricultural land-use plans. This research has three phases. The major outcome of the first phase is collecting the agricultural and water resources utilization data such as soils, rivers, streams, collective farms, etc., designing and building database, and developing integrated management system considering the users' requirements. The main work of the second phase is improving and reinforcing database such as adding the information of dams, land-over data, bridges, tunnels, satellite images, etc., inspecting and renewing such as importing detail attribute information of reservoirs, and improving system for more conveniently using. The third phase will be to supplement more useful functions such as statistic analysis, continually inspecting and improving database, and developing web-based system. The product of this research supports collecting and analyzing relevant data to facilitate easier agricultural activities and support effective decision making for food production in the preparation of unification. Moreover, through designing database considering sharing information and system expendability, it can support systematic data usability of agricultural information and save cost for data management.

• Spatial Information Research
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• v.23 no.4
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• pp.47-56
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• 2015

Recently, there has been an increase in the number of people who use the smart-phone navigation for using various latest functions such as group driving and location sharing. But smart-phone has a limited storage space for one application, since a lot of applications with different purposes are installed in the smart-phone. For this reason, road network data with a large space of memory used for map matching in the device for navigation cannot be stored in the smart-phone for this reason map matching is impossible. Besides, smart-phone which doesn't use the external GPS device, provides inaccurate GPS information, compared to the device for navigation. This is why the smart-phone navigation is hard to provide accurate location determination. Therefore, this study aims to help map matching that is more accurate than the existing device for navigation, by reducing the capacity of road network data used in the device for navigation through format design of a new road network and conversion and using a database of driver's driving patterns. In conclusion, more accurate map matching was possible in the smart-phone by using a storage space more than 80% less than existing device at the intersection where many roads cross, the building forest that a lot of GPS errors occur, the narrow roads close to the highway. It is considered that more accurate location-based service would be available not only in the navigation but also in various applications using GPS information and map in the future Navigation.

• Journal of the Korean Geographical Society
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• v.46 no.4
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• pp.534-553
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• 2011

Analogical thinking is a problem-solving strategy to use a familiar problem (or base analog) to solve a novel problem of the same type (the target problem). The purpose of this study is to provide new insight into geography teaching and learning by connecting cognitive science research on analogical thinking with issues of geography education and suggest that teaching with analogies can be a productive instructional strategy for geography. In this study, using the various examples of analogical thinking used in geography we defined analogical thinking, addressed the theoretical models on analogical transfer, and discussed conditions that make an effective analogical transfer. The major research findings include the following: a) the spatial analogy, indicating skills to find places that may be far apart but have similar locations, and therefore have other similar conditions and/or connections, can provide a useful way to design contents for place learning; b) representational transfer, specifying a common representation for two problems, can play a key role in solving geographic problems requiring data visualization and spatialization processes; and c) either asking learners to compare/analyze similar examples sharing common structure or providing them examples bridging the gap between concrete, real-life phenomena and the ideas and models can contribute to learning in geographic concepts and skills. The spatial analogy requiring both geographic content knowledge and visual/spatial thinking has the potential to become a content-specific problem-solving strategy. We ended with recommendations for future research on analogy that is important in geography education.

• Journal of the Korean Regional Science Association
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• v.38 no.1
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• pp.21-32
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• 2022

The purpose of this study is two things. First, it is to develop and demonstrate a sharong taxi platform. To this end, the implications for platform development were derived by analyzing consumers' perceptions of existing taxi services using IPA. As a result, abnormal business activities and safe services in the maintenance area were found to be safe rides and easy rides in the key improvement area. Safety such as usage fee level and driver information provision were derived in the areas subject to improvement, and friendly response and internal and external cleanliness were derived in the areas of excessive investment. The second purpose of this study is to estimate the value given to users for sharing taxi service platforms using the CVM. As a result of estimating the value of the demonstration service of the shared taxi platform developed through this study, the WTP was 3,621 won/per household/per year when expanding throughout Gimhae-si, and 2,515 won/per household/per year. Compared to the willingness to pay for empirical services, only 69.5% of the willingness to pay for the spread project in Gimhae-si. This is the result of a combination of service spread to an unspecified number of people and concerns about service quality due to spatial expansion. This suggests that it is necessary to build data through continuous demonstration and to carefully build a roadmap for spread by upgrading services based on this.

• Journal of Wetlands Research
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• v.13 no.3
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• pp.593-602
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• 2011

The estuarine area of the ecological environment had been seriously damaged by reckless developments during the past half century. The demand for management in estuarine area increased but the efficient management system did not exist. Therefore the aim of this study is to develop a GIS-based integrated DB management system by integrating the ecological environmental data of each division in estuarine area. To achieve this, the system used integrated DB. It is classified into a surveyed monitoring DB in 2010 at estuarine area of Yeongsan and GIS DB to express the spatial data. The integrated DB management system was developed using VisualBasic.NET languages and Arcobjects component for Map-based spatial analysis. Also, to improve the utilization of data, the composition of GUI(Graphical User Interface) through user needs analysis, the expression of monitoring DB, the priority of layer and the function for modular unit were defined. Ultimately the system was developed based on the defined items. GIS-based integrated DB management system can support to understand the ecological environment in estuarine area of Yeongsan river. Also it will provide the users with effective sharing and environmental management of the data. In the future study, comprehensive diagnosis for ecological environment in estuarine area and the reliable prediction need to be made by connecting modeling system.